# Decision Record ## Decisions - Treat the clavichord as a tangent-keyed string instrument where touch after contact is part of the acoustic mechanism. - Uplift the packet to L2 by adding candidate part classes, coupon-test gates, and service/safety review points. - Keep all dimensions, tuning, tangent coordinates, pressure values, string gauges, CAD, and DXF work out of the L2 packet. - Preserve fretted/listed and unfretted layouts as explicit open branches. - Make the first physical work a one-key tangent test rig before any complete keyboard or case design. ## Assumptions - Brass tangents strike strings from below and define pitch while the key is pressed. - Bebung depends on stable tangent contact and controllable after-pressure. - Fretted/listed layouts trade independence for fewer string courses. - Unfretted layouts trade added load and hardware for note independence. ## Open Questions - Which historical or measured clavichord family should govern the first L2 parameter set? - Should the first branch study a fretted/listed layout, an unfretted layout, or a removable action that can compare both? - What tangent face and adjustment method gives clear attack without buzz? - What damping layout preserves dynamic touch and bebung? - How should string load, case stiffness, and service access be reviewed before a full packet? - Which one-key coupon layout can compare tangent face, return behavior, and damping without implying a full keyboard scale? - What evidence is required before a fretted/listed note-conflict map can become a layout decision? ## Next Work - Select a measured reference frame. - Build a one-key tangent/string/damper test rig. - Log attack, release, buzz, bebung control, and dynamic range. - Compare fretted/listed and unfretted implications with a note-conflict and load review. - Record safety and serviceability observations before readiness is upgraded. - Promote beyond L2 only after the coupon and reference evidence produce reviewed parameters, not from this concept packet.